Regulatory T cells

Regulatory T cells (Tregs) are CD4⁺ T cells that inhibit autoreactive effector T cells to suppress antitumor immunity. Many anticancer therapeutics have limited efficacy, and it is thought that Tregs may, in part, be one of the reasons. From this viewpoint, Tregs may be a therapeutic target for cancer immunotherapy. Tregs also play a pivotal role in the induction of self-tolerance, and their dysfunction may lead to autoimmune disease. Promising results have recently been reported on the molecular targeting of drugs to Tregs. In the near future, the regulation of Tregs may be a central point for cancer immunotherapy. In this chapter, we focus on the immune-suppressing mechanism of Tregs and the development of strategies to modulate Tregs.